Harvard University Law School Public Law & Legal Theory Research Paper SeriesUniversity of Chicago Law School Public Law & Legal Theory Research Paper Series Paper No. 199~and~University of Chicago Law School Law & Economics Research Paper Series Paper No. 387

Conspiracy Theories

CASS R. SUNSTEIN University of Chicago - Law School ADRIAN VERMEULE Harvard University - Harvard Law School This paper can be downloaded free of charge from theSocial Science Research Network at:http://ssrn.com/abstract=1084585

Many millions of people hold conspiracy theories; they believe that powerful people have worked together in order to withhold the truth about some important practice or some terrible event. A recent example is the belief, widespread in some partsof the world, that the attacks of 9/11 were carried out not by Al Qaeda, but by Israel or the United States. Those who subscribe to conspiracy theories may create serious risks,including risks of violence, and the existence of such theories raises significant challenges for policy and law. The first challenge is to understand the mechanisms bywhich conspiracy theories prosper; the second challenge is to understand how suchtheories might be undermined. Such theories typically spread as a result of identifiablecognitive blunders, operating in conjunction with informational and reputationalinfluences. A distinctive feature of conspiracy theories is their self-sealing quality.Conspiracy theorists are not likely to be persuaded by an attempt to dispel their theories;they may even characterize that very attempt as further proof of the conspiracy. Becausethose who hold conspiracy theories typically suffer from a “crippled epistemology,” inaccordance with which it is rational to hold such theories, the best response consists incognitive infiltration of extremist groups. Various policy dilemmas, such as the questionwhether it is better for government to rebut conspiracy theories or to ignore them, areexplored in this light.

conspiracy theories are all around us. In August 2004, apoll by Zogby International showed that 49 percent of New York City residents, with a

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Karl N. Llewellyn Distinguished Service Professor of Jurisprudence, University of Chicago.

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Professor of Law, Harvard Law School. Thanks to Mark Tushnet for helpful conversations, to EricPosner and Andrei Shleifer for valuable comments, and to Elisabeth Theodore for excellent researchassistance.

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This slogan was popularized by the television show The X-Files, see http://en.wikipedia.org/wiki/The_X-Files. 9/11 conspiracy theorists often call themselves the 9/11 Truth Movement.

In a Scripps-Howard Poll in 2006, with an error margin of 4percent, some 36 percent of respondents assented to the claim that “federal officials eitherparticipated in the attacks on the World Trade Center or took no action to stop them.”

Conspiracy theories are by no means a strictly domestic phenomenon; they caneasily be found all over the world. Among sober-minded Canadians, a September 2006poll found that 22 percent believe that “the attacks on the United States on September 11,2001 had nothing to do with Osama Bin Laden and were actually a plot by influentialAmericans.”

What causes such theories to arise and spread? Are they important and perhapseven threatening, or merely trivial and even amusing? What can and should governmentdo about them? We aim here to sketch some psychological and social mechanisms thatproduce, sustain, and spread these theories; to show that some of them are quite importantand should be taken seriously; and to offer suggestions for governmental responses, bothas a matter of policy and as a matter of law.The academic literature on conspiracy theories is thin, and most of it falls into oneof two classes: (1) work by analytic philosophers, especially in epistemology and thephilosophy of science, that asks what counts as a “conspiracy theory” and whether suchtheories are methodologically suspect;

Both approaches haveproved illuminating, but neither is entirely adequate, the former because the conceptualquestions are both less tractable and less interesting than the social and institutional ones,the latter because it neglects newer work in social psychology and behavioral economics,both of which shed light on the causes of conspiracy theorizing. Rather than engaging

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Zogby International,

Half of New Yorkers Believe US Leaders Had Foreknowledge of Impending 9-11 Attacks and “Consciously Failed” To Act